# test `fast' substitutions h s/a// p g s/a//g p g s/^a//p g s/^a//g p g s/not present//g p g s/^[a-z]//g p g s/a$// p g y/a/b/ h s/b// p g s/b//g p g s/^b//p g s/^b//g p g s/^[a-z]//g p g s/b$// p g